1. Field of the Invention
This invention relates generally to magnetic tape players which have a mechanism for controlling the tape drive device so as to change the direction in which the tape is driven.
2. Description of the Prior Art
Various mechanisms have been proposed for use in cassette tape players to provide automatic reversing of the tape drive direction. Typically, the direction in which the tape is driven is automatically changed or reversed when the tape is completed unwound from the supply reel to the take-up reel during operation in the playback mode of the tape player. Further, manual changing of the direction of tape drive at some point before detection of the tape end during operation in the playback mode requires the addition of only a few relatively simple parts to such automatic reversing mechanisms. In general, a direction-changing button is mounted in such mechanisms so as to be manually operated for changing the tape drive from the normal direction to the reverse direction, and from the reverse direction to the normal direction, with both such direction changes occurring while the tape player remains in its playback mode established by the forward mode button being held in its operative or depressed position.
In the above mechanism, although the tape drive direction should be reciprocally changed whenever the direction-changing button is operated or the tape end is detected, it is also necessary, for the convenience of the operator, that the tape be driven in the normal direction whenever the forward mode button is initially operated or depressed while the tape player is in its stop mode. Therefore, regardless of the direction in which the tape was being driven before return to the stop mode, it is necessary that the tape be driven in the normal direction when the forward mode button is operated or depressed with the tape player in the stop mode. This requires in addition, a so called "priority device", for example, as disclosed, but not claimed, in co-pending U.S. patent application Ser. No. 06/652,571, filed Sept. 20, 1984, and having a common assignee herewith.
In the mechanism disclosed in the above-identified application, a gear which has an eccentric thereon rotates once through 360.degree. to cause a change lever to move to-and-fro whenever the tape end is detected or the direction-changing button is operated. A slider for changing the tape drive device and a lock lever for locking the slider at one position are reciprocally moved by the to-and-fro movement of the change lever. When a forward mode button resumes its inoperative or inactive position in response to establishing of the stop mode, the lock lever is returned to its inoperative position for releasing the slider. Therefore, the above-mentioned "priority device" function is achieved in a relatively easy way.
However, the typical tape player of today is intended for portable use so that miniaturization of its size is of importance. It is not desirable in such portable tape players to provide a mechanism including a change lever moved to-and-fro whenever a change of tape direction is to occur because it results in wasting of space in the player, especially for the movement of a change lever with a slanted posture as described in the above-identified application.
Moreover, several attempts have been made to save space in a tape player by using a gear having a pair of diametrically opposed cutout portions or toothless gaps. For example, as shown in U.S. Pat. No. 3,976,263, which also has a common assignee herewith, an apparatus has been developed for controlling a tape drive device which, in its forward mode, can drive the tape only in a normal direction, and which has a change member movable between first and second positions in response to each turn of a gear through 180.degree.. Although it may be possible to apply this type of gear to the existing mechanism for changing the tape drive direction in the playback mode, substantial modification of such mechanism is required, particularly in achieving the above-mentioned "priority device" function without undesirably increasing the space required therefor in the tape player.